1. Field of Invention
This invention relates generally to equipment for loading of a payload and more particularly to an apparatus for determining a spatial positioning of the loading equipment.
2. Description of Related Art
Operation of heavy loading equipment such as electric mining shovels and cranes generally involves an operator controlling the equipment based on visual feedback of the position of an operating implement of the equipment. However, the operator's view of the operating implement and surrounding environment may be constrained by a limited field of view or perspective due to the operator's location in a cab of the loading equipment. For example, in electric mining shovels (also called cable shovels or rope shovels) used for excavating and loading ore using a dipper, the placement of the operator in the cabin is quite removed from the actual operation of the dipper.
Collision between loading equipment and objects or obstacles in the surrounding environment is a serious safety concern, and may also result in damage to the loading equipment. It is also possible that an operator may overload and overstress the operating components of loading equipment by subjecting the equipment to excessive forces, due to a lack of feedback from the controls.
Monitoring systems that sense the spatial positioning of components of the loading equipment on the basis of relative displacement between components have two drawbacks:
(1) They usually require re-initiation from time to time to calibrate the system as they may rely on signals generated by sensors such as potentiometers or resolvers, for example. When the loading equipment is powered down, the calibration information may be lost and the system will require recalibration.
(2) Mining shovels also typically operate in a harsh environment in which there is high likelihood of sensors on the operating components being damaged due to impact or due to ingress of dirt and debris. Systems that rely on signals produced from a plurality of sensors disposed at different locations on key components of the equipment are particularly prone to failure.
There remains a need for improved methods and apparatus of monitoring the spatial positioning of operating implements of loading equipment.